Question

我尝试解密加密文本并使用此代码，但是向我收到此错误：

Exception in thread "main" java.security.InvalidKeyException: Illegal key size

和解密代码是：

String key = "ffce885876a617e7";
    String vector = "9ee153a3df56965e7baf13a7fa1075cc";


    IvParameterSpec ivSpec = new IvParameterSpec(key.getBytes());
    SecretKeySpec keySpec = new SecretKeySpec(vector.getBytes(), "AES");


    Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
    cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec); //error occured in this line

Answer 1

.getBytes()不会自动将“十六进制字符串”转换为匹配的字节。

相反，请尝试使用此实用程序方法：

private static byte[] hexStringToBytes(final String input)
{
    final int len = input.length();
    if (len % 2 != 0)
        throw new IllegalArgumentException();

    final byte[] ret = new byte[len / 2];
    int offset = 0;

    for (int i = 0; i < ret.length; i++) {
        ret[i] = (byte) Integer.parseInt(input.substring(offset, offset+2), 16);
        offset += 2;
    }

    return ret;
}

然后在您的代码中使用hexStringToBytes(key)等

Answer 2

我用这个来解密AES。但是在Android环境中而不是Java vanila。

public String decrypt(String enc) throws Exception {
    try {
        String key = "ffce885876a617e7";
        String vector = "9ee153a3df56965e7baf13a7fa1075cc";

        IvParameterSpec ivSpec = new IvParameterSpec(key.getBytes());
        SecretKeySpec keySpec = new SecretKeySpec(vector.getBytes(),
                "AES");

        Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
        cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);

        return new String(cipher.doFinal(hexToByte(enc)), "UTF-8");

    } catch (Exception localException) {
        throw new Exception("[decrypt] " + localException.getMessage());
    }
}

private static byte[] hexToByte(String enc) {
    int j = enc.length() / 2;
    byte[] arrayOfByte = new byte[j];

    if (j >= 2) {
        for (int i = 0; i < j; i++) {
            arrayOfByte[i] = ((byte) Integer.parseInt(
                    enc.substring(i * 2, 2 + i * 2), 16));
        }
    }
    return arrayOfByte;
}

java中的AES加密错误

2 个答案: